Micro-Electro-Mechanical Systems (MEMS) optical systems employ an optical bench with various optical elements operable to control transmission of light through the system. Such optical elements may include lens, fully reflecting mirrors, partially reflecting mirrors, and/or wave guides. Some optical elements, such as the fully and partially reflecting mirrors, are manually placed on the optical bench or placed on the optical bench by a ‘pick and place’ machine. Such mirrors are then aligned and fixed into place.
The process of placing, aligning, and fixing one or more mirrors on an optical bench is a time consuming process that is relatively expensive. The difficulty and cost of placing, aligning, and fixing mirrors on the optical bench is further compounded as devices become smaller.
Wave guides may be used to precisely route light through an optical device. Since silicon is light transmissive, wave guides may be formed on the optical bench as part of the fabrication process. However, some applications require that the light be transmitted through free space. The free space may be filled with a gas, or the free space may be a vacuum. Accordingly, routing of transmitted light through free space requires fully and/or partially reflecting mirrors.
Accordingly, it is desirable to precisely control routing of light through free space in a MEMS optical bench. While fully and/or partially reflecting mirrors may accurately control the routing of light through a MEMS optical bench, the use of such mirrors suffers a serious disadvantage, namely that it is difficult and expensive to place, align, and fix such mirrors on the optical bench, particularly if by-hand alignment of the mirrors is required.